Double digit Arguments Passed to Shell script - Tricky Scenario

Guys, you know that $# is a special variable that gives the arguments passed to the shell script.

$1 will give the 1st argument passed, $4 will give the 4th argument passed to the script.

Let's consider a tricky scenario. 
Note : This is a tricky interview question.

Let's say you want to pass 12 arguments to the script.

Did you notice that after 9th argument, all arguments passed would be of 2 digits... I mean the 10th, 11th and 12th argument.

So let's say to get the 12th argument, you may tend to use $12. But hey look again! Thats not right! The script doesn't understand that. Check out a practical example to know what I mean.

Let's take a simple bash script and compare the output of Wrong and Correct versions.

[WRONG VERSION]

#!/bin/bash

# Call this script with 12 parameters

echo "1st parameter is $1";

echo "2nd parameter is $2";

echo "3rd paramter is $3";

echo "4th parameter is $4";

echo "5th paramter is $5";

echo "6th parameter is $6";

echo "7th parameter is $7";

echo "8th paramter is $8";

echo "9th parameter is $9";

echo "10th parameter is $10";

echo "11th parameter is $11";

echo "12th paramter is $12";

Now lets say you execute the script with 12 arguments. Watch the output :

./Parameters_Pass.sh 5 10 15 20 25 30 32 35 42 45 50 65

1st parameter is 5

2nd parameter is 10

3rd paramter is 15

4th parameter is 20

5th paramter is 25

6th parameter is 30

7th parameter is 32

8th paramter is 35

9th parameter is 42

10th parameter is 50

11th parameter is 51

12th paramter is 52

See how the 10th 11th and 12t argument that we passed got screwed up. Instead of 45, 50, 65 what we see is 50, 51 and 52. Thats's so wrong, right?

Now here's the correct version of the script.

[CORRECT VERSION]

#!/bin/bash

# Call this script with 12 parameters

echo "1st parameter is $1";

echo "2nd parameter is $2";

echo "3rd paramter is $3";

echo "4th parameter is $4";

echo "5th paramter is $5";

echo "6th parameter is $6";

echo "7th parameter is $7";

echo "8th paramter is $8";

echo "9th parameter is $9";

echo "10th parameter is ${10}";

echo "11th parameter is ${11}";

echo "12th paramter is ${12}";

Observe the brace brackets used for 10th, 11th and 12th argument. Now if you execute the script with 12 arguments again, we'll get the correct output as expected.

./Parameters_Pass.sh 5 10 15 20 25 30 32 35 42 45 50 65

1st parameter is 5

2nd parameter is 10

3rd paramter is 15

4th parameter is 20

5th paramter is 25

6th parameter is 30

7th parameter is 32

8th paramter is 35

9th parameter is 42

10th parameter is 45

11th parameter is 50

12th paramter is 65